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bill tindall
01-31-2014, 10:13 AM
History of the rediscovery of the Kato and Kawai work and video on the cap iron(chip breaker) effect

It was quite an accident

Steve Elliot has been doing research on plane blades and planing for several years. I was following Steve’s work posted on his web site. During some discussion he directed me to a publication by Professor Kato on plane blade wear. Steve also made me aware of some “screen shots” he had posted on his web site that were taken from a long lost video on what Professor Kato calls the “cap iron effect”. This paper referenced some additional publications on plane blade wear that Steve was interested in. When I tried to obtain these publications I found them to be in obscure Japanese technical journals. Professor Kawai is still teaching and through the University library I was able to track him down in the midst of the Japanese Tsunami tragedy (the university was closed). He in turn put me in touch with Professor Kato who generously volunteered to send me copies of the publications. He mentioned off hand that he had a planing video he could send. Indeed, it was the “lost” video.

Professor Kato’s research was on plane blade wear, specifically for the Japanese Super Surfacers, planing machines that replicate the surface finish of hand planing. A laboratory planing machine was developed for these studies. The planing machine enabled videos of shaving formation to be made. Professors Kato and Kawai realized that these pictures would be a useful teaching tool in their trades classes. They prepared a video for this purpose. This video was presented by Professor Kato at the 3rd International Tooling Symposium in 1994. There was interest in this video and Professor Kato put it up for at time on the University web site. Some screen shots from this video got captured and it was these shots that found their way to Steve’s web site. However, without the complete text to go with them they were not as informative as they could be.

Steve’s focus at the time was on blade wear and he needed a translation of Kato’s publication on this topic. One of our club members, Mia Iwasaki, graciously volunteered to translate the publication. Because the publication is copyrighted we could not repost it. But, a review of the paper was prepared and it is posted on Steve’s site. There are several other important publications on wear that we will post when we are able to get them translated.
When I received the copy of the video from Professor Kato , I asked Mia to translate the audio which she did. In the mean time Professor Kawai agreed to put the video back up on the University web site. In various places, for example Weaver article at Wood Central, there are links to this video.

Kato and Kawai published a description for setting the cap iron (chip breaker) as a teaching tool for their classes. We have not gotten this publication thoroughly translated at this time. ( If anyone can translate Japanese to English we have several planing papers that would be of interest that need translation. One in particular is on wear and sharpening of various plane blade steels.) In this paper they use the compression of the shaving to judge when the cap iron is properly set. It is this shaving compression that provides the counter force to resist the lifting of the shaving ahead of the plane blade tip.

I have in hand the original copy of the Kato and Kawai video. I have permission from Professor Kato to share it so long as it is not used for any commercial purpose( like don’t make copies and sell them!). Ideally, it will get stored in enough places that I will not get lost again.

David Weaver
01-31-2014, 11:00 AM
Bill, what drove you and steve to dig up the study information initially, was it just curiosity or did you have some frustration (like I did) with Warren's plain (but correct) statements about needing nothing other than a single iron? My apologies for making a weak link to Warren vexing us all for a while if that really had nothing to do with it.

I ended up on the wrong side of a lot of arguments with Warren, though, and it took longer to realize that Warren has the same very thorough theoretical and well-developed through practice conservation quality thoughts that George would (talking with george over a question you have is being able to get a definitive answer, a complete museum quality explanation of the history and commentary of practical proof of it). I made a few bad assumptions in late 2011 and early 2012 (one misremembering the study in the back of the Lee book as a picture of double irons at work, and two that warren had won the WIA planing contest with a bailey #4 against several planes that cost a few thousand dollars. Adam Cherubini said something about that back then - i specifically recall a comment that warren outplaned one of konrad sauers smoothers with a basic stanley #4, and I'm still trying to piece together where I heard it. Warren since said he won the WIA contest with a plane he had no (little?) experience with - a LV bevel up plane).

Yours and steve's work, and the work of some of the folks like brent beach (who has one of the definitive wear test for various production irons available, one that I've never found a disagreement with on anything) has been extremely helpful - digging up items unavailable to us or and creating original content that we would never otherwise get from an unbiased source, and maybe not at all. Steve's quantifying the total angle that various irons stop chipping out is also extremely helpful, as is the quantification of sharpness of various steels with various sharpening mediums in planing wood - precise data derived from experimentation rather than maybes, sort ofs, or kind ofs or could bes.

bill tindall
01-31-2014, 11:29 AM
I was just trying to help Steve find some papers to support his seminal work on blade wear. Steve does excellent work and it should be supported however it can be. He is an exceptionally researcher.

I never planed much, well hardly at all. Never could avoid tear-out. Frankly I was so cynical about planing that I didn't even take the Kato work seriously until "Kees did it" (inside joke). Nothing like a practical demonstration to get your attention. I still don't plane unless it is faster than sanding, but now I don't fear tear-out. I opened up two plane mouths so the shaving would not jam, set the cap iron effectively close and now I seldom even bother to note which way the grain is going. Tight mouths never worked in my hands and they are totally unnecessary with the cap iron properly set. I just finished planing the figured front edges of the front of a chest of drawers (posted on WoodCentral). Zero stress, zero tear-out. Now I plane more, thanks to Kees.

David Weaver
01-31-2014, 11:39 AM
I was just trying to help Steve find some papers to support his seminal work on blade wear.

It's interesting that the videos were found then because you and steve were actually looking for something else (blade wear and nothing to do with chipbreakers).

I do remember you saying "if kees can do it, I can do it" back then, I think we all got a chuckle out of that and hoped that kees wouldn't be offended :) If it's only warren, then it's probably too hard, but if kees shows you he can on a short video, then it must be attainable :)